1. Field of the Invention
The present invention relates to a method for detecting when a vehicle brake light is not functioning due to either a brake light bulb burning out or the fuse blowing that controls the electrical circuit for the brake lights. In particular, the invention relates to a Microcontroller Unit (MCU) functionally controlling the circuit between a vehicle's brake lights and the fuse controlling the light bulbs.
2. Description of Related Art
Motor vehicles such as cars, trucks, sport vehicles, or the like all have safety lights such as turn signals, brake lights, running lights, and parking lights each with one or more light bulbs. These lights are controlled from the inside and normally have a replaceable or electronic fuse that is a safety mechanism in the electrical system. The inability to know if a light is out and if it is out is it due to the light bulb burning out or the fuse blowing while the vehicle is being operated is a common problem experienced by all vehicle operators.
It is clear that the inoperability of the light bulb in these lights can create a hazardous and illegal driving situation. Frequently, the only way to manually check brake lights is to have a second person stand outside the vehicle while the brake pedal is pressed and to get down on ones hands and knees to check fuses.
Accordingly, some attempts have been made to provide electronic indication. In patent application 2006/0017540, there is a dual bipolar LED indicator light circuit connected between the blades of a blade fuse. When the fuse blows, an LED lights up on the device to indicate a blown fuse. The device only deals with the fuse and requires visual access to the fuse box to see the LED. Frequently, the fuse box is sealed making visualization impossible, not to mention that there is little or no room to utilize the device.
In U.S. Pat. No. 6,218,952 issued Apr. 17, 2001 there is a system for detecting a blown light system in a trailer being pulled by a vehicle by monitoring a decrease in the current level as a key parameter for determining if there has been a failure in the light signal circuit. It cannot detect the difference between a blown fuse and a blown light bulb.